COLLECTION, ISOLATION, IDENTIFICATION, AND BIOSYNTHESIS OF SILVER NANOPARTICLES USING MICROALGA CHLORELLA PYRENOIDOSA

Abstract

The samples were collected from rock ponds in Kovalam, isolated with the aid of plating techniques, and identified at the Krishnamurthy Institute of Algology, Chennai. Algal cells were grown in a Bolds Basal medium and cultured for 14 days for 16:8 h at 24°C. In 14 days the algal cells were pelleted by centrifugation. The bioreduction of Ag+ ions in solution was monitored by means of the UV-visible spectroscopy from zero reading, and doubly distilled water was used as a blank. The samples were withdrawn at various time intervals and the absorbance was measured at 450 nm. The silver nanoparticles synthesized using extracts of algal samples was confirmed by color changes and was characterized by a UV-visible spectrophotometer; the UV-visible spectra showed a broad peak located at 450 nm for silver nanoparticles. The TEM analysis shows small spherical 5−10-nm-sized particles. The nanoparticles were also characterized by the SEM, EDAX, XRD, and FTIR analysis.